int A :: b; what does this instruction mean?

Question

the above code is declared below a class 'A' and b is the data member of the class A.

Answer 1

:: is the scope resolution operator. It's used to access and initialize static class or namespace members.

Answer 2

Because that's the default value.

Answer 3

class A {
public:
static int b;
};

int A::b;

int main()
{
A x;
cout << x.b;
}

i get the out put has '0' but i didnt declare the value for b then how?

and what does " int A: b; " mean in this program??

also i just started learning c and c++😅

Answer 4

@ helioform yeah i can get it
but i have not initialized the value of 'b' anywhere then how does it print the value has "0".

Answer 5

A::b mean A derive class, b base class.. did you really read and learn the C++ course ?